And the events of 358/2 Days bleed into Kingdom Hearts II. We watch as Roxas lives out his last week as a "normal everyday boy" when everything decides to go crazy. Roxas meets up with Nobodies and receives the Keyblade; seemingly for the first time, as his memory was erased.
He also meets up with Axel. Axel, in 358/2 Days, was a dear friend of his, but he has no memory of this. Since Roxas is unwilling to come, Axel has no choice but to destroy him. But he is rather reluctant in the deed and never does.
Eventually, Roxas also meets up with Naminé, who tells him to come to the old haunted mansion. He soon does, with the aid of the Keyblade, and he has an odd experience there when looking at a picture of him and Sora, who he has never seen. This triggers total recall, restoring all of his memories, for the most part.
Roxas soon heads to the mansion’s basement and meets up with Sora. Being his Nobody, the two fuse together…
A year after going comatose, the 15-year-old Sora, as well as Donald and Goofy, awaken from their slumber. It is obvious from their daze that their Castle Oblivion memories are not there anymore, nor is Jiminy’s record of their journey there, and they have no idea where they are.
As they travel around Twilight Town, Sora experiences a lot of nostalgia from Roxas’s time there. They also meet up with Nobodies and are saved from the onslaught by King Mickey, who tells them to board the train.
When they do, they meet up with one of the villains from Kingdom Hearts I, or at least one of Maleficent’s lackeys: Pete, who is building a Heartless army for her.
They defeat him and ascend the nearby tower to meet with Yen Sid, the King’s teacher. He gives them help in journeying across the worlds with a new Gummi Ship, new clothes, and so on.
During their journey, they continually find themselves bombarded by both Organization XIII and Maleficent. The Organization wants Sora to continually slay Heartless for them, which releases hearts, which are used to make Kingdom Hearts appear.
Also during the journey, it is revealed that a scientist under the real Ansem, a wise man who studies the worlds, was named Xehanort. Xehanort was one day turned into a Heartless, like many of Ansem’s apprentices, and also turned into a Nobody.
The Heartless half named itself Ansem, and was slain by you. The Nobody half is named Xemnas, and is the leader of Organization XIII. Many of the apprentices had similar things occur to them, including having Nobodies join the Organization.
Eventually, the trio reach their stronghold, The World That Never Was. There, Sora meets up with Riku and Kairi and Riku’s changed looks are cured. All but the leader of the Organization (and Roxas, technically) are slain. Xemnas summons Kingdom Hearts and flees inside.
And so, Sora, Riku, and King Mickey use their Keyblades to open Kingdom Hearts so they can go inside and defeat Xemnas.
They seemingly do and, as they flee through a portal of darkness, Sora and Kairi meet up with a ghosty Roxas and Naminé. The meeting is cut short when, with only Riku and Sora on the tower, the tower begins to collapse.
After a final epic battle with Xemnas, who is slain, Sora and Riku find themselves in a world of darkness. There, the lights of their hearts open a door. They go through it and find themselves rocketing down to the Destiny Islands, their home… They meet up with Kairi, King Mickey, Donald, and Goofy.
Some time later, Sora, Kairi, and Riku receive a note from the King. A note whose text is unread to the player until…